This invention relates to escalators and more particularly to curved escalators which have a stairway path that is curved in plan.
Typical circular or curved escalators have a stairway path along which a series of steps travel, the path having a constant radius of curvature or circular in plan throughout its entire length including the horizontally-moving landing sections at the upper and lower ends of the escalator. The stairway path is defined by guide tracks that support and guide various rollers mounted on the steps. The guide track on the outer side of the circular stairway path and the guide track on the inner side of the circular stairway path are different in gradient. Therefore, with guide tracks of a constant radius of curvature as in the escalator described above, the distance between the axes of step axles that connect the step to the driving chain must be variable in order that the angular velocities of the step at the outer and inner side of the step be equal even in locations where the angle of slope changes, such as in the transition portions between the load-bearing inclined portion and the upper or lower horizontal landing portion. This requires a complex and expensive driving and guiding arrangement in the escalator.